Production of sea lice for research and studies of sea louse biology and their interactions with hosts
1. Purpose
Sea Lice Research Centre (SLRC) aim to study details on sea louse biology with the purpose of developing new and environmentally friendly treatments against sea lice, hereunder vaccines, better drugs and other new methods. Except for vaccine testing, all research is carried out on sealice, which are not subjected to animal welfare regulations. However, fish are needed as hosts to maintain specific sea lice strains and to produce the required material for research.
2. Distress
This research requires a limited number of standard operations carried out on host fish, inducing mild discomfort: 1) infecting fish with sea lice copepodids. 2) Anesthetizing fish for collection/counting lice. 3) Adding preadult or adult lice directly to anesthetized fish. 4) In selective breeding on lice, it will be necessary to de-louse fish using commercially available de-lousing agents at recommended dosages, including freshwater. 5) Vaccinating fish to test new vaccine candidates using a) DNA vaccines and B) Antigen based vaccines. 6) Tagging fish using either a) elastomere implants, b) pit tags. In the cases where fish is infected with Caligus elongatus, moderate distress is expected in the period when the lice become adult. Even though C. elongatus eat far less from its host, it annoys the fish more than salmon lice.
3. Expected benefits
The expected benefits from these studies are to obtain the fundamental knowledge on sea louse biology required to construct novel treatments, and to test new candidate treatments.
4. Number of animals
The maximal number of fish used will remain under 2000 salmonid hosts per year over a four-year period. We therefore apply to use a maximal total number of 8000 salmonids, where the overall majority of these will be Salmo salar. To improve animal welfare when maintaining cultures of Caligus elongatus (skottelus), we also aim to test a new cultivation procedure for skottelus by using lumpsuckers as hosts for adult lice instead of salmon. If successful, we aim to establish this as a new procedure and aim to use a maximum of 500 lumpsuckers per year, in total 2000 C.lumpus over 4 years.
5. Adherence to 3R
Since sea lice are obligate parasites, replacement of the host species is unfortunately not an option. For efficacy studies like RNAi, vaccines and drugs we have limited the number of hosts to an absolute minimum by using single fish tanks (Hamre 2011) and by deciding that we will aim to detect only substantial effects (in general >50%). Small scale studies of louse biology are also carried out in such tanks since these allow detailed monitoring of each host and its parasites in absence of agonistic host-host interaction, and thereby avoiding a higher use of hosts involved in more traditional experimental designs in communal tanks. Factors to enhance animal welfare are transparent tanks or tanks with windows fitted with nets on top, optimal current of flow, special nets for netting and calm behavior near fish tanks avoiding dark clothing. We also attempt to find better adapted host (lumpfish) for "skottelus" since they annoy the salmon.
The pink salmon will be used for exploring the relationship between host and parasite, and will not be subjected to any other experimental treatments. They will not be used for vaccine testing or to produce lice for other research. Samples of fish (sampled post mortem) and lice will subjected to analysis of gene expression.
Sea Lice Research Centre (SLRC) aim to study details on sea louse biology with the purpose of developing new and environmentally friendly treatments against sea lice, hereunder vaccines, better drugs and other new methods. Except for vaccine testing, all research is carried out on sealice, which are not subjected to animal welfare regulations. However, fish are needed as hosts to maintain specific sea lice strains and to produce the required material for research.
2. Distress
This research requires a limited number of standard operations carried out on host fish, inducing mild discomfort: 1) infecting fish with sea lice copepodids. 2) Anesthetizing fish for collection/counting lice. 3) Adding preadult or adult lice directly to anesthetized fish. 4) In selective breeding on lice, it will be necessary to de-louse fish using commercially available de-lousing agents at recommended dosages, including freshwater. 5) Vaccinating fish to test new vaccine candidates using a) DNA vaccines and B) Antigen based vaccines. 6) Tagging fish using either a) elastomere implants, b) pit tags. In the cases where fish is infected with Caligus elongatus, moderate distress is expected in the period when the lice become adult. Even though C. elongatus eat far less from its host, it annoys the fish more than salmon lice.
3. Expected benefits
The expected benefits from these studies are to obtain the fundamental knowledge on sea louse biology required to construct novel treatments, and to test new candidate treatments.
4. Number of animals
The maximal number of fish used will remain under 2000 salmonid hosts per year over a four-year period. We therefore apply to use a maximal total number of 8000 salmonids, where the overall majority of these will be Salmo salar. To improve animal welfare when maintaining cultures of Caligus elongatus (skottelus), we also aim to test a new cultivation procedure for skottelus by using lumpsuckers as hosts for adult lice instead of salmon. If successful, we aim to establish this as a new procedure and aim to use a maximum of 500 lumpsuckers per year, in total 2000 C.lumpus over 4 years.
5. Adherence to 3R
Since sea lice are obligate parasites, replacement of the host species is unfortunately not an option. For efficacy studies like RNAi, vaccines and drugs we have limited the number of hosts to an absolute minimum by using single fish tanks (Hamre 2011) and by deciding that we will aim to detect only substantial effects (in general >50%). Small scale studies of louse biology are also carried out in such tanks since these allow detailed monitoring of each host and its parasites in absence of agonistic host-host interaction, and thereby avoiding a higher use of hosts involved in more traditional experimental designs in communal tanks. Factors to enhance animal welfare are transparent tanks or tanks with windows fitted with nets on top, optimal current of flow, special nets for netting and calm behavior near fish tanks avoiding dark clothing. We also attempt to find better adapted host (lumpfish) for "skottelus" since they annoy the salmon.
The pink salmon will be used for exploring the relationship between host and parasite, and will not be subjected to any other experimental treatments. They will not be used for vaccine testing or to produce lice for other research. Samples of fish (sampled post mortem) and lice will subjected to analysis of gene expression.